function render() {
  console.log('视图渲染')
}
let obj = {
  name: '柚子',
  age: { x: 0, y: { a: 5 } },
  arr: [1, 2, 3],
}
let handler = {
  get(target, key) {},
  set(target, key, value) {},
}
let proxy = new Proxy(obj, handler)
